So what? She can enjoy the moment. She can let herself be cared for by him, she has to only be careful and build her fences high not to fall for him, and revenge will come later when she has the strength to defeat them.
She just has to fool around, play with his emotions and shatter his heart in the end, that is the trick. Romance revenge won't be such a bad idea.
"What are you afraid of?" He asked.
Good question, "I'm afraid you might break my heart if you regain your memory and find out I am not the girl you loved, you might that I deceived...